download assistant still doesnt work and and to Change the win clock time sync doesnt work either! 
I just went to the Steinberg.net site, login, and under Support, go to ‘Chat.’ Took just a couple of minutes to connect and get an associate. Then he gave me a link and password to a yamaha site where all the Cubase11 files are located. I am downloading as I type here.
And yes, my St. Download Assis. is not working either, and appears to be stuck at the ‘authorize SDA’ level.
I had this problem yesterday. Kept going round in circles trying to authorise it. I uninstalled and then downloaded it again. Still didn’t work the first few times but eventually it did.